Robocall Blocking Fails

Last year, there was some hope of a technological solution to robocalls. Now that hope is all but gone.

Robocalls are phone calls placed by machine to deliver a recorded message, sometimes to phone numbers on a list, more often to numbers selected at random. They’re used by scammers and politicians. By all estimates they account for a significant fraction of all phone calls in the United States.

They’re also illegal in almost all cases, but enforcement is rare. Robocallers are rarely identified. Only about one a year faces a fine over $1 million. They never go to jail.

There are dozens of initiatives to try to block robocalls, and they work, but not well enough. The best ones block about half of robocalls, but at considerable cost. A small fraction of legitimate calls are blocked too. Americans are spending billions of hours a year reporting robocalls, but meanwhile, the number of robocalls keeps going up. And in recent months, the effectiveness of robocall blocking has been dropping off as robocallers adopt less obvious tactics.

The problem is similar to the one that nearly killed email, but the solutions that bought time for email won’t help with phone calls. You can’t filter the content of a real-time voice conversation until the conversation is already underway.

The only answer known so far is whitelisting; that is, we will have to stop taking calls from phone numbers we don’t recognize. Obviously, that means giving up on the promise of the voice network. Station-to-station real-time conversations for which all you need is a phone and a phone number won’t be practical after the network is clogged with robots. But people are already pulling back: canceling home phone service, removing desk phones and voice mail from offices, refusing calls from random area codes. If shutting down the phone network is the solution, we are already halfway there.